Daewoo Rf 420 Service Manual

							FUNCTIONS
A. “TEMP” Button
 1. Temperature control of Refrigerator compartment
 2. 5 step mode of successive temperature mode
 3. Initial mode by power input: step “3”
 4. Temperature will be set if the button doesn’t get pressed again within 5 sec.
    - Whenever pressing “TEMP” button, setting is repeated in the order of
          “3” → “4” →  “5” → “1” →  “2”  (LED LAMP ON)
B. Temperature of Refrigerator Control
 1. COMP and FAN will be controlled by the on/off condition of each mode.1
 2. Temperature Difference of Refrigerator each step :
 
 
 3. Temperature of Refrigerator
       at step “3” OFF point: is  -1.4C
 
 4. Refrigerator ON/OFF Temp.
       Difference: 1.7C
C. “S-COOL” MODE
1. Press S-COOL SWITCH
    and make S-COOL led lamp on.
2. COMP & FAN are on
 until R-sensor
     reaches to “Over Refrigeration
     OFF Point”, -7C
3. After the reach of -7°C , STEP “5” mode continues.
4. When “S-COOL” MODE (Quick Refrigeration Mode)
    lasts for about 40 minutes, it returns to general
    operation mode.
D. Temperature of Freezer Control
-It will be only controlled by using
 “KNOB F LOUVER” in Freezer.
 PCB Control Panel LED
 COMPRESSOR, FAN
CONTROL OBJECT INPUT
  PCB Control Panel “TEMP” Buttons
 R-sensor  2. Temperature Control of Refrigerator Compartment
Step      1           2         3          4         5
ON
OF Temp
Dial
4.3 C
2.3 C0.3 C
-1.7 C-3.7 C
2.6 C
0.6 C-1.4 C-3.4 C
-5.4 C “5” “4” “3” “2” “1”
Temperature Step
2.0C 2.0C 2.0C 2.0CTemp. Diff. of Each Step
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							FUNCTIONS
Defrost Mode
A. When total operation time of compressor becomes: 6, 8, 10, 12 hours.
  - any error mode-R1, D1, F3, C1, RT/S, Door SW error- happens.
  - or, running rate of COMP (per 2hrs of total operation time) is more than 80%.
  - or, total door open time is over 3 minutes.
  - or, ambient temperature (RT) is more than 40C.
B. Even if the above condition “A” is not satisfied,
  - Defrost mode starts immediately when total operation time of COMP is 14hrs.
  - or, defrost mode starts immediately as long as total time (COMP on time + COMP off time) is 60 hrs.
A. General Defrost Mode
 - How to start: By conditions of defrost
 - Process :
   General operation-
   “PRE-COOL” - Defrost Heater on- Pause (10 min)-General operation
   ; PRE-COOL: When the defrost heater works, the temp. of freezer increases.
         So the COMP works for 25 min before defrost mode.
 - Limited Time of Defrost Heater
   ; 40 minutes: Heater turns off when “D SENSOR” is OPEN or SHORT.
   ; 60 minutes: Heater turns off after maximum 60 minutes.
 - Heater Off: When the temperature at “D SENSOR” is over 10C
B. Forced Defrost Mode
 - How to start:  by press “TEMP” button for continuously and “S-COOL” button 5 times.
 - Process: same as General Defrost Mode except “PRE-COOL”
    ; Heater is supposed to be on Initial 30 seconds even though the temp. at “D SENSOR” is over 10C.
      (for TEST)
 - How to confirm: by press “S-COOL” button for continuously and “TEMP” button 5 times.
                           And then, the mode displays.
 - Display : led lamps “3”& “S-COOL” on, “4” & ”5” on/off continually
CONTROL OBJECT INPUT
 Total COMP Work Time  /  COMP Working Rate
Total Door Open Time  / 
 RT
 3. Defrost Mode
 Conditions of Defrost Mode
 Defrost Mode
OFF ON OFFDefrostOFF OFF ON
FanOFF OFF ON
Compressor
PauseDefrostPRE-COOL
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							A. When initial power input or returning power failure.
    if the temperature at the Defrost Sensor is below 3.5 C, Defrost Mode starts.
    ( It prceeds from PRE-COOL ),  [ PRE-COOL - Heater On - Pause (10min) - Normal Operation ]
B. Initial defrost mode starts after Prevention of Compressor Restart. ( Refer to function No. 5 )
FUNCTIONS
 Initial Defrost
 Flow Chart of Defrost Start
Defrost Mode
CONTROL OBJECT INPUT
 Total COMP Work Time / COMP Working Rate
 Total Door Open Time   / RT
 3. Defrost Mode
Comp time >= 2 hours
Start
Total time >= 60 hours
Comp time >= 14 hours
Comp time >= 6 hours
Comp Rate >= 80%
Any Error?
RT Temp >= 40C
Total door open time >= 3min?
ENDDefrosting Start
Yes
Yes
Yes
Yes
Yes
Yes
YeYesNo
No No
No
No
No
No
No
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							FUNCTIONS
R-HTR
COMP
A. Condition of LOW RT
  - LOW RT Period : RT sensor below 19C
  - When the temperature of RT sensor is over 20C, the system comes to be “General Operation Mode”.
  - When the temp. of RT sensor is between 19°C to 20C, the system keeps the previous mode.
B. Control
  - When Comp. is on, R-HTR is off.
  - When it passes 6 min after COMP is off, R- HTR is on.
  - COMP can’t be on within 30 min after COMP is off.
       ; COMP doesn’t work at the steps “Heater On” and “Pause”  of  “Defrost Mode”.
            If COMP comes to be off  for “Low Room Temp” in the steps, it seems to take over 30 minutes.
  - Change of “Prevention Time of COMP Restart” :
       If satisfy the following conditions simultaneously, the time changes 6 minutes.
        
; Accumulated running time of COMP passes 20 seconds after COMP is off.
        
; R-Sensor is more than ‘ON’ Point TEMP.
  - When it is not the mode of LOW ROOM TEMP
      or RT-Sensor is on ERROR (open or short), R-Sensor HTR is off.
  - Function of R-Heater Inspection:
       After initial power is on, R-HTR is on/off 5times for 10 seconds.
  - When Defrost Heater is on, R-Sensor Heater is on
CONTROL OBJECT INPUT
 RT
4. Function of Low Ambient Temperature (RT)
COMP
COMP. doesn’t work after COMP turns off even though R-sensor is on condition. (This is to protect comp.)
A. General operation (Temp. at the RT sensor is over 20C): The COMP can’t be on within 6 min.
B. Operation of LOW RT (Temp. at the RT sensor is below 19C):
     The COMP can’t be on within 30 min.
     (But the COMP can be on after 6min when the doors open more than 20 seconds.)
CONTROL OBJECT INPUT  5. Prevention of Compressor Restart
Buzzer
A. Whenever  “PCB Control Panel” button’s pushed, the buzzer rings.
B. After 2 minutes power’s on, the buzzer rings 3 times.
C. Time of Buzzer: Forced Defrost Mode (3 times), Short Circuit Test (1 time)
D. When door opens, the buzzer rings every 1 minute for 5 minutes.
CONTROL OBJECT INPUT
Control Buttons   / Door Switch
Initial Power Input
6. Buzzer Sound
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							FUNCTIONS
 Buzzer
A. HOW TO REDUCE
    -   1 min : Click FAST KEY one time on MAIN PCB.
    - 30 min : If you press FAST KEY continuously, you can reduce 30 minutes on each 2.5 seconds with
buzzer.
B. Practice Use : Can be applied to reduce needless time on test.
    EX
) function of stop for 6 min
CONTROL OBJECT INPUT
 ”FAST KEY”
7. Time Reduction
Display Panel
A. START : by pressing “TEMP” and “S-COOL” buttons for 5 seconds.
B. CONTROL :
   - All electronic compartments are off except “Display Panel”.
   - When “DEMO” mode works, led lamps will be on as next steps.
        [ “1”  → “2” → “3” → “4” → “5” → “1”]
C. CANCEL :
    Push again “TEMP” and “S-COOL” buttons for 5 seconds at “DEMO”, or turn off power and restart.
CONTROL OBJECT INPUT
 “TEMP” +”S-COOL” Buttons
8. Demonstration Function
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							FUNCTIONS
Control Resistance of R sensor OFF Point
A. LOW COOLING OPTION ( Weak Cooling )
    - When the refrigeration of refrigerator is poor or weak though Fan and COMP are working continuously,
         the following actions are recommended for service.
         
- Resistance (R47) :  Default resistance (31.4Kohms)
              - Resistance (R45) :  Cut the “J1” off to reduce basic resistance by 1.5°C. (2Kohms up)
              - Resistance (R42) :  Cut the “J2” off additionally to reduce basic resistance by 1.5°C. (total 4Kohms
up)
     R47 = R-SENSOR OFF point
     R47 + R45 = R-SENSOR OFF point - 1.5C
     R47 + R45 + R42 = R-SENSOR OFF point - 3C
 
 
CONTROL OBJECT INPUT
 ”J1” , “J2”  On Main PCB
 9. Control of R-sensor OFF Point
R-SENSOR
J2
R47(31.4K)
R45(2K)
R42(2K)J1
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							FUNCTIONS
B. Prevention OPTION of EXCESSIVE OR LOW COOLING.
 
;  The input voltage of MICOM and R-Sensor ON/OFF point by changing J3 & R30.
 
OPTION 3
(P63)  26PIN
CC3 J3 R32 R31
R30MICOM 5VVa
 Input voltage of MICOM
 R-sensor ON/OFF Point
CONTROL OBJECT INPUT
  ”J3” & “R30” On Main PCB
 9. Control of R-sensor OFF Point
+1.7C 5VJ3(CUT), R30(NO USE)0.3C 2.0C 11+1.4C 4V
J3(CUT), R30 (40.2kohm)0C 1.7C 10+1.1C 3.3V
J3(CUT), R30 (19.6kohm)-0.3C 1.4C 9+0.7C 2.5V
J3(CUT), R30 (10kohm)-0.7C 1.0C 8+0.4C 2.0V
J3(CUT), R30 (6.65kohm)-1.0C 0.7C 7-0.4C 1.6V
J3(CUT),  R30 (4.87kohm)-1.8C -0.1C 6-0.7C 1.4V
J3(CUT),  R30 (3.92kohm)-2.1C -0.4C 5-1.1C 1.1V
J3(CUT),  R30 (2.8kohm)-2.5C -0.8C 4-1.4C 0.8V
J3(CUT),  R30 (2kohm)-2.8C -1.1C 3-1.7C 0.3V
J3(CUT),  R30 (680ohm)-3.1C -1.4C 2STANDARD 0V
- -1.4C 0.3C 1INPUT VOL. (MAIN PCB) OFF ONCompared to
“STANDARD” MICOM APPLICATION
TEMP. STEP “3”
NO
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							FUNCTIONS
 Input voltage of MICOM
 R-sensor ON/OFF Point
C. Changing Difference between R-sensor “On” point and “Off” point.
 
 ; The input voltage of MICOM and R-Sensor ON/OFF DIFF. by changing J4 & R23.
 
CONTROL OBJECT INPUT
  ”J4” & “R23” On Main PCB
9. Control of R-sensor OFF Point
OPTION 2
(P64)  27PIN
CC6 J4 R28 R25
R23MICOM 5VVa
3.9C 5VJ4(CUT), R23(NO USE)-1.4C 2.5C 113.5C 4V
J4(CUT), R23 (40.2kohm)-1.4C 2.1C 103.2C 3.3V
J4(CUT), R23 (19.6kohm)-1.4C 1.8C 92.8C 2.5V
J4(CUT), R23 (10kohm)-1.4C 1.4C 82.5C 2.0V
J4(CUT), R23 (6.65kohm)-1.4C 1.1C 72.1C 1.6V
J4(CUT),  R23 (4.87kohm)-1.4C 0.7C 61.4C 1.4V
J4(CUT),  R23 (3.92kohm)-1.C 0C 51.1C 1.1V
J4(CUT),  R23 (2.8kohm)-1.4C -0.3C 40..7C 0.8V
J4(CUT),  R23 (2kohm)-1.4C -0.7C 30.4C 0.3V
J4(CUT),  R23 (680ohm)-1.4C -1.0C 21.7C 0V
- -1.4C 0.3C 1INPUT VOL. (MAIN PCB) OFF ONDIFFERENCE OF
ON/OFF POINT MICOM APPLICATION
TEMP. STEP “3”
NO
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							FUNCTIONS
 LED Lamp
- ERROR DISPLAY
   - To confirm error happens or not, push S-COOL” button for continuously and “TEMP” button 5 times.
   - To stop the Error Display Set, push “TEMP” button 1 times, or wait 4 minutes.
   - After operations back to normal, the displays come to be reset.
A. R1 ERROR
  (It happens when R-Sensor is OPEN or SHORT)
 -  DISPLAY : STEP “3” LED is on & off continually.
 -  CONTROL :
    ; Controlled by the following condition of RT
    ; When “RT ERROR” happens at the same time, “COMP. ON/OFF Operating Time” is 16min/24min.
                                                                                                                        (Unit : min)
 
 - CANCEL : when R-Sensor is working normally.
B. RT ERROR
 (It happens when RT-Sensor is OPEN or SHORT)
 - DISPLAY : STEP “2” LED is on & off continually.
 - CONTROL : Delete the conditions of “RT-sensor Control” and operate normally.
 - CANCEL : when RT-Sensor is working normally.
C. D1 ERROR
 (It happens when D-Sensor is OPEN or SHORT)
 - DISPLAY : STEP “1” LED is on & off continually.
 - CONTROL : Return to next limit defrost time  (40 min)
 - CANCEL : when D-Sensor is working normally.
D. DR ERROR
   (It happens when the system senses door opens more than 1 hour.)
 - DISPLAY : STEP “2”, “3” LED Lamps are on & off continually.
 - CONTROL : Deletion of function related door switch sensing
 - If door switch (open & close) is sensed, the error is terminated
        automatically
E. C1 ERROR
   (When D-Sensor is more than -5C, Comp operates over 3 hrs)
 - DISPLAY : STEP “1” & “3” LED Lamps are on & off continually.
 - CONTROL : The system is normally operating
 - CANCEL : When Comp is off, D-Sensor is less than -5C.
F. F3 ERROR
 Return to next step after max defrost ti me.
 ( 60 minutes )
 6.1- DISPLAY : STEP “1” & “2” LED Lamps are on & off continually.
 6.2- CONTROL : At Defrost Mode, Deletion of “PRE-COOL” Mode.
 6.3- CANCEL : Completion of defrost returned by D-Sensor.
- If the appliance is normal (no error), just 4 and 5 LED flicker in Error Mode.
CONTROL OBJECT INPUT
 PCB Control Panel Buttons / Door
10. Error Display
6/34
~13C
10/30~19C
16/24~29C
20/20
COMP. Operating TIME
(ON/OFF)
29C ~RT sensor TEMP
- To Confirm Errors:
Push “S-COOL” for
continuously and “TEMP”
button 5 times.
- The Priorities of Error :
    R1→RT→D1→DR→C1→F3 Defrost
“1”, “2” F3Cycle
“1”, “3” C1DR Switch
“2”, “3” DRD sensor “1” D1RT sensor “2” RTR sensor “3” R1
ERRORLEDCODE
flicker
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							11. Function Key Summary Table
( 1 - 2 - 3 - 4 - 5 - 1 ) Forced Defrost Mode
Pull Down Mode
Error Display
Demo Mode
Display
 In Error Mode, you can find the current mode ( What mode is operationg ) and what kinds of Error happen.How to terminate Temp + S-Cool button for 5 seconds
LED Lamps will be on as next steps. Display 4, 5 LED flicker (When no error happens)
How to enter the Mode Temp + S-Cool button for 5 seconds How to enter the Mode S-Cool + Temp button 5 times
How to terminate emp button 1 time or after 4 minutes How to terminate After Mode ends ( about 30 hour ) 
Display 1, S-Cool LED ON (In Error Mode) Display 3, S-Cool LED ON (In Error Mode)
How to enter the Mode Temp button 30 times How to enter the Mode Temp + S-Cool button 5 times
How to terminate After Mode ends ( about 1 hour ) 
FUNCTIONS
MODE Action Button / Remark 
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